#include "usart2.h"
#include "stdio.h"

u8 USART2_RX_BUF[USART_REC_LEN]; 
u16 USART2_RX_STA=0; 

void uart2_init(u32 bound)
{
	 //GPIO端口设置
	GPIO_InitTypeDef GPIO_InitStructure;
	USART_InitTypeDef USART_InitStructure;
	NVIC_InitTypeDef NVIC_InitStructure;
	 
	RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART2,ENABLE);	//使能USART2时钟
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA,ENABLE);	//使能GPIOA时钟
	USART_DeInit(USART2);  //复位串口2
	 //USART2_TX   PA.2
	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2; //PA.2
	GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;	//复用推挽输出
	GPIO_Init(GPIOA, &GPIO_InitStructure); //初始化PA2
 
	 //USART2_RX	  PA.3
	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_3;
	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;//浮空输入
	GPIO_Init(GPIOA, &GPIO_InitStructure);  //初始化PA3
 
 
	//USART 初始化设置
 
	USART_InitStructure.USART_BaudRate = bound;//一般设置为9600;
	USART_InitStructure.USART_WordLength = USART_WordLength_8b;//字长为8位数据格式
	USART_InitStructure.USART_StopBits = USART_StopBits_1;//一个停止位
	USART_InitStructure.USART_Parity = USART_Parity_No;//无奇偶校验位
	USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;//无硬件数据流控制
	USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;	//收发模式
 
	 USART_Init(USART2, &USART_InitStructure); //初始化串口

	//Usart1 NVIC 配置
	NVIC_InitStructure.NVIC_IRQChannel = USART2_IRQn;
	NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=3 ;//抢占优先级3
	NVIC_InitStructure.NVIC_IRQChannelSubPriority = 3;		//子优先级3
	NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;			//IRQ通道使能
	NVIC_Init(&NVIC_InitStructure);	//根据指定的参数初始化VIC寄存器
 
	USART_ITConfig(USART2, USART_IT_RXNE, ENABLE);//开启中断
	USART_Cmd(USART2, ENABLE);                    //使能串口 
 
}
void USART_SendString(USART_TypeDef* USARTx, char *DataString)
{
	int i = 0;
	USART_ClearFlag(USARTx,USART_FLAG_TC);										//发送字符前清空标志位（否则缺失字符串的第一个字符）
	while(DataString[i] != '\0')												//字符串结束符
	{
		USART_SendData(USARTx,DataString[i]);									//每次发送字符串的一个字符
		while(USART_GetFlagStatus(USARTx,USART_FLAG_TC) == 0);					//等待数据发送成功
		USART_ClearFlag(USARTx,USART_FLAG_TC);									//发送字符后清空标志位
		i++;
	}
}

void USART2_IRQHandler(void)
{
	u8 Res;
	if(USART_GetITStatus(USART2, USART_IT_RXNE) != RESET)  //接收中断(接收到的数据必须是0x0d 0x0a结尾)
		{
		Res =USART_ReceiveData(USART2);	//读取接收到的数据
		if((USART2_RX_STA&0x8000)==0)//接收未完成
			{
			if(USART2_RX_STA&0x4000)//接收到了0x0d
				{
				if(Res!=0x0a)USART2_RX_STA=0;//接收错误,重新开始
				else {
					USART2_RX_STA|=0x8000;	//接收完成了 
				}
				}
			else //还没收到0X0D
				{	
				if(Res==0x0d)USART2_RX_STA|=0x4000;
				else
					{
					USART2_RX_BUF[USART2_RX_STA&0X3FFF]=Res ;
					USART2_RX_STA++;
					if(USART2_RX_STA>(USART_REC_LEN-1))USART2_RX_STA=0;//接收数据错误,重新开始接收	  
					}		 
				}
			}   		 
     } 
	
}
